Author pages redirect to Main page after upgrade

Crossposted from here

Hey all ,I've juss upgraded my WP installation and for some reason it seems that the author pages are now redirecting to the main page immediately. The site uses a custom author.php that used to work normally before the upgrade.

You can see it here:
Just click on any author name and you'll be redirected back.

I'm using the Royale 1.4 theme.

You can see my author.php here:

Thanks!